The present invention relates generally to antenna systems in portable communications devices.
Many portable communications devices, including cellular handsets, personal digital assistants, smart phones, laptops, notebooks, netbooks, and tablet computers, include two or more radio communications devices operating independently and simultaneously in the same frequency band or adjacent frequency bands. For example, many devices use both Bluetooth and 802.11 radios for wireless networking. Bluetooth and 802.11n operate in the same frequency band at 2.4 to 2.5 GHz, and can interfere with each other and reduce the performance of either or both communication streams. To improve performance, high isolation is needed between the antenna ports used for the two radios.